Cationic polyurea cover compositions for a multi-layer golf ball

ABSTRACT

Golf balls that have at least one layer formed from a cationic polyurea material. In particular, the compositions of the invention, which include a polymer backbone including urea linkages with cationic groups, may be formed from an isocyanate-containing component and an isocyanate-reactive component, at least one of which includes precursor cationic groups, in the presence of an alkylating, quaternizing, or ternarizing agent.

FIELD OF THE INVENTION

The present invention relates to golf balls that have at least one layerformed from a cationic polyurea material. In particular, thecompositions of the invention, which include a polymer backboneincluding urea linkages with cationic groups, may be formed from anisocyanate-containing component and an isocyanate-reactive component inthe presence of an alkylating, quaternizing, or ternarizing agent. Inanother embodiment, the compositions of the invention are formed byreactive extrusion of an isocyanate prepolymer or monomer in thepresence of an amine moiety with a post-polymerization reaction byalkylating, quaternizing, or ternarizing agents. The compositions of theinvention may be used in any outer layer of a golf ball, e.g., an outercover layer or inner cover layer, or may be used as a coating to bedisposed over a structural outer layer of a golf ball.

BACKGROUND OF THE INVENTION

Golf ball manufacturers have been experimenting with various materialsand manufacturing methods for golf balls over the years in an attempt toimprove overall performance and durability and to further refine themanufacturing process.

For example, over the past years, golf ball manufacturers have beenusing ionomer resins for golf ball cover materials because of thedurability, rebound, and scuff resistance characteristics of thematerials. However, while ionomer resins are more durable than othertypes of golf ball layer materials, the same properties that result indurability also provide a hard “feel” and generally result in a lowerspin rate and, thus, lower control, due to the hardness of the material.

Alternatively, polyurethane compositions produce “soft” covers andtypically allow for greater control because of the increased spin.Because conventional polyurethane cover materials are typically formedof aromatic components, the ultraviolet degradation of the material,which leads to yellowing, led to the recent trend toward light stablecover materials, such as aliphatic polyurethane and polyurea materials.Whether aromatic or aliphatic in nature, however, the relative softnessof the polyurethane and polyurea materials introduces durability issues.

Further attempts to compensate for the “hard” feel of ionomer-coveredgolf balls and durability and adhesion issues with polyurethane-coveredand polyurea-covered golf balls have resulted in blends of hard ionomerresins, i.e., resins with hardness values of about 60 Shore D and above,with relatively softer polymeric materials. For example, blends of hardionomers with polyurethanes have been used to form intermediate layersand cover layers of golf balls. However, such blends generally haveprocessing difficulties associated with their use in the production ofgolf balls due to the incompatibility of the components. In addition,golf balls produced from these incompatible mixtures will have inferiorgolf ball properties such as poor durability, cut resistance, and thelike.

As such, a need exists in the golf ball art for materials that have theperformance benefits of polyurethane and/or polyurea, but also havedesirable resiliency and compatibility to decorative layers such aspaints and inks. In addition, golf balls having layers formed, at leastin part, from such compositions would be advantageous. The presentinvention addresses such materials, methods of forming the materials,and portions of golf balls formed from these materials.

SUMMARY OF THE INVENTION

The present invention is directed to a golf ball including a core and acover, wherein the cover includes a polymer including: a polyureaprepolymer including an isocyanate-containing component and anisocyanate-reactive component, wherein the polyurea prepolymer includesbetween about 1 and about 50 percent cationic groups by weight of thepolyurea prepolymer; and a curative including: an amine-terminatedcuring agent; and a neutralizing agent having the general formula QXwhere Q includes hydrogen, an alkyl group, a benzyl groups, or acombination thereof and X includes a monovalent anion.

In this aspect of the invention, the cover may include an inner coverand an outer cover and either or both of the cover layers may be formedfrom the polymer. In one embodiment, the outer cover includes thepolymer. In another embodiment, the inner cover includes the polymer.

In one embodiment, the isocyanate-reactive component includes a primarydiamine, a secondary diamine, a primary triamine, a secondary triamine,or a mixture thereof. In another embodiment, the isocyanate-reactivecomponent includes a primary triamine or a secondary triamine.

The present invention also relates to a golf ball including a core and acover, wherein the cover includes a polymer including: a polyureaprepolymer including the reaction product of an isocyanate-containingcomponent and an isocyanate-reactive component, wherein theisocyanate-reactive component has one of the following generalstructures:H₂N—R₁—NH₂;R₂HN—R₁—NHR₂;R₃R₂N—R₁—NR₂R₃;H₂N—R₁—NHR₂;R₃R₂N—R₁—NH₂; orR₃R₂N—R₁—NHR₂where R₁ includes unsubstituted or substituted straight chain orbranched aliphatic groups, unsubstituted or substituted aromatic groups,or mixtures thereof, wherein R₂ and R₃ independently include an alkylgroup, an aryl group, or an aralkyl group, and wherein the polyureaprepolymer includes between about 5 percent and about 25 percentcationic groups by weight of the prepolymer; and a curative including anamine-terminated compound.

In this aspect of the invention, the curative may further include aneutralizing agent having the general formula QX, wherein Q includeshydrogen, an alkyl group, a benzyl groups, or a combination thereof andX includes a monovalent anion. In addition, the cationic groups may beselected from the group consisting of ≡N^(⊕)—, ≡P^(⊕)—, ═S^(⊕)—, andmixtures thereof.

The cover may include an inner cover layer and an outer cover layer. Inone embodiment, the inner cover layer includes the polymer. In analternate embodiment, the outer cover layer includes the polymer.

The present invention is also directed to a golf ball including at leastone layer including a polymer including a polyurea prepolymer formedfrom the reaction product of a diisocyanate and an amine-terminatedcomponent, wherein the polyurea prepolymer includes between about 1percent and about 50 percent cationic groups selected from the groupconsisting of ≡N^(⊕)—, ≡P^(⊕)—, ═S^(⊕)—, and mixtures thereof; and acurative including: an amine-terminated curing agent and a neutralizingagent, where the amine-terminated curing agent may have at least one ofthe following general formulas:H₂N—R₁—NH₂;R₂HN—R₁—NHR₂;R₃R₂N—R₁—NR₂R₃;H₂N—R₁—NHR₂;R₃R₂N—R₁—NH₂; orR₃R₂N—R₁—NHR₂where R₁ includes unsubstituted or substituted straight chain orbranched aliphatic groups, unsubstituted or substituted aromatic groups,or mixtures thereof, wherein R₂ and R₃ independently include an alkylgroup, an aryl group, or an aralkyl group. The polymer may bethermoplastic or thermoset.

In this aspect of the invention, the neutralizing agent may have thegeneral structure QX, wherein Q includes hydrogen, an alkyl group, abenzyl groups, or a combination thereof and X includes a monovalentanion. In one embodiment, the monovalent anion includes fluoride,chloride, bromide, iodide, hydroxide, carbonate, and mixtures thereof.Furthermore, the golf ball may include a core, an intermediate layerdisposed about the core to form an inner ball, and a cover disposedabout the inner ball, and wherein the cover is formed from the polymer.In such a construction, the intermediate layer may be formed from athermoplastic material. Alternatively, the intermediate layer may beformed from the polymer.

The present invention is also directed to a golf ball including at leastone layer including a composition including: a polyarea prepolymerformed from the reaction product of a diisocyanate and anamine-terminated component; a curative including: an amine-terminatedcuring agent having at least one of the following general formulas:H₂N—R₁—NH₂;R₂HN—R₁—NHR₂;R₃R₂N—R₁—NR₂R₃;H₂N—R₁—NHR₂;R₃R₂N—R₁—NH₂; orR₃R₂N—R₁—NHR₂where R₁ includes unsubstituted or substituted straight chain orbranched aliphatic groups, unsubstituted or substituted aromatic groups,or mixtures thereof, wherein R₂ and R₃ independently include an alkylgroup, an aryl group, or an aralkyl group, and wherein theamine-terminated curing agent further includes about 5 percent to about25 percent precursor cationic groups by weight of the amine-terminatedcuring agent; and a neutralizing agent, wherein between about 20 percentand 70 percent of the precursor cationic groups are neutralized.

In this aspect of the invention, the curative may further include a flowmodifier. In addition, the precursor cationic groups may include atleast one of a tertiary amine, a phosphine, and a sulfide. Furthermore,the neutralizing agent may have the general structure QX, wherein Qincludes hydrogen, an alkyl group, a benzyl groups, or a combinationthereof and X includes a monovalent anion, where the monovalent anionmay include fluoride, chloride, bromide, iodide, hydroxide, carbonate,and mixtures thereof.

Moreover, the golf ball in this aspect of the invention may include acore, an intermediate layer disposed about the core to form an innerball, and a cover disposed about the inner ball, and wherein the coveris formed from the composition and the intermediate layer may be formedfrom any suitable intermediate layer. For example, in one embodiment,the intermediate layer is formed from a thermoplastic material.Alternatively, the intermediate layer may be formed from the compositionand the cover may be formed from any suitable cover material.

The present invention also relates to a golf ball including a core and acover, wherein the cover includes a composition including: a polyureaprepolymer formed from the reaction product of a diisocyanate and anamine-terminated component; a curative including: an amine-terminatedcuring agent including between about 1 percent to about 50 percentprecursor cationic groups by weight of the amine-terminated curingagent; and a neutralizing agent having the general structure QX, whereinQ includes hydrogen, an alkyl group, a benzyl groups, or a combinationthereof and X includes a monovalent anion. The composition may bethermoplastic or thermoset.

In this aspect of the invention, the cover may include an inner coverlayer and an outer cover layer. In one embodiment, the inner cover layerincludes the composition. In another embodiment, the outer cover layerincludes the composition. In addition, between about 20 percent and 70percent of the precursor cationic groups may be neutralized. Moreover,the composition may further include a flow modifier and allow greaterthan about 70 percent of the precursor cationic groups are neutralized.

In one embodiment, the precursor cationic groups include ≡N, ≡P, ═S′ ora combination thereof. In another embodiment, the amine-terminatedcuring agent includes between about 5 percent to about 25 percentprecursor cationic groups by weight of the amine-terminated curingagent.

The present invention is also directed to a golf ball including a coreand a cover, wherein the cover includes a castable reactive liquidmaterial including: a polyurea prepolymer formed from the reactionproduct of a diisocyanate and an amine-terminated component; and acurative including an amine-terminated curing agent including betweenabout 1 percent to about 50 percent cationic groups by weight of theamine-terminated curing agent, wherein the cationic groups are selectedfrom the group consisting of ≡N^(⊕)—, ≡P^(⊕)—, ═S^(⊕)—, and mixturesthereof.

In one embodiment, the cover includes an inner cover layer and an outercover layer. In this aspect of the invention, the inner cover layer mayinclude the polymer. Alternatively, the outer cover layer may includethe polymer.

The amine-terminated curing agent may include between about 5 percent toabout 25 percent precursor cationic groups by weight of theamine-terminated curing agent.

A golf ball including at least one layer including a compositionincluding: a polyurea prepolymer formed from the reaction product of adiisocyanate and an amine-terminated component; a curative including anamine-terminated curing agent having at least one of the followinggeneral formulas:H₂N—R₁—NH₂;R₂HN—R₁—NHR₂;R₃R₂N—R₁—NR₂R₃;H₂N—R₁—NHR₂;R₃R₂N—R₁—NH₂; orR₃R₂N—R₁—NHR₂where R₁ includes unsubstituted or substituted straight chain orbranched aliphatic groups, unsubstituted or substituted aromatic groups,or mixtures thereof, wherein R₂ and R₃ independently include an alkylgroup, an aryl group, or an aralkyl group, and wherein theamine-terminated curing agent further includes about 1 percent to about50 percent cationic groups by weight of the amine-terminated curingagent. The composition may be thermoplastic or thermoset.

In one embodiment, the golf ball includes a core, an intermediate layerdisposed about the core to form an inner ball, and a cover disposedabout the inner ball, and wherein the cover is formed from thecomposition. In this aspect of the invention, the intermediate layer maybe formed from a thermoplastic or thermoset material.

In another embodiment, the golf ball includes a core, an intermediatelayer disposed about the core to form an inner ball, and a coverdisposed about the inner ball, and wherein the intermediate layer isformed from the composition.

The amine-terminated curing agent may include between about 5 percentand 25 percent cationic groups by weight of the amine-terminated curingagent.

The present invention is also directed to a golf ball including a core,an intermediate layer disposed about the core, and a cover disposedabout the intermediate layer, wherein at least one of the intermediatelayer and cover is formed of a composition including: a polyureaprepolymer formed from the reaction product of a diisocyanate and anamine-terminated component; and an amine-terminated curing agentincluding between about 5 percent to about 25 percent cationic groups byweight of the amine-terminated curing agent, wherein the cationic groupsare selected from the group consisting of ≡N^(⊕)—, ≡P^(⊕)—, ═S^(⊕)—, andmixtures thereof.

In this aspect of the invention, the intermediate layer may include athermoplastic material. In addition, the composition used to form thecover may be thermoset or thermoplastic.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features and advantages of the invention can be ascertained fromthe following detailed description that is provided in connection withthe drawing(s) described below:

FIG. 1 is a cross-sectional view of a two-piece golf ball, wherein thecover is formed from a composition of the invention;

FIG. 2 is a cross-sectional view of a multi-component golf ball, whereinat least one layer is formed from a composition of the invention;

FIG. 3 is a cross-sectional view of a multi-component golf ball having alarge core, wherein at least one layer is formed from a composition ofthe invention; and

FIG. 4 is a cross-sectional view of a multi-component golf ballincluding a dual core and a dual cover, wherein at least one layer isformed from a composition of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed to golf balls including at least onelayer formed from a cationic polyurea composition. In particular, thecompositions of the invention include a polyurea reaction product thatcontains cationic groups in the backbone of the polymer.

The compositions of the invention provide an alternative for a golf ballmanufacturer to use on a traditional ionomer-covered ball orurethane-covered ball. In fact, without being bound to any particulartheory, golf balls that include the compositions of the invention ascover layers have improved resilience, abrasion and impact resistance,and compatibility with paints and inks. As such, golf balls of thepresent invention, e.g., golf balls including cover layers formed fromthe compositions of the invention, may replace conventional golf ballsincluding a dual cover system with a hard inner cover layer and a softouter cover layer at least because the improved properties of thecompositions will provide the benefits previously achieved with the dualcover system. In addition, the compositions of the invention may be usedin an inner cover layer to achieve a superior ball as compared to a ballformed using conventional ionomers to form the inner cover.

The present invention also explores the methods of making suchcompositions and other golf ball constructions that incorporate thecompositions of the invention in at least a portion thereof. In fact,the compositions of the invention can be used with a variety of golfball constructions. For example, the compositions of the invention maybe used as a cover layer in a two-piece ball with a large core, an outercover layer in a three-piece ball with a relatively thin inner coverlayer, an intermediate layer in a three-piece ball, or an inner coverlayer in a golf ball having dual cover layers. The compositioncomponents, golf ball constructions, and layer and ball properties arediscussed in greater detail below.

The Compositions of the Invention

The compositions of the invention may be formed in several ways,however, the resultant product is covalently incorporated orfunctionalized with cationic groups, which can impart desirableproperties to the resulting polymer materials. In one embodiment, thecomposition is formed by first reacting an isocyanate-containingcomponent with an isocyanate-reactive amine-terminated component to forma prepolymer containing urea linkages and then chain extending theprepolymer with an amine-terminated curative blend. Any or all of theisocyanate-containing components, isocyanate-reactive amine-terminatedcomponents, or curative may include at least one precursor group of acationic group before, during, or after the prepolymer formation or thecuring reaction. As such, the precursor groups of cationic groups can beneutralized to corresponding cationic groups before, during, or afterthe prepolymer formation or the curing reaction. The resultingcomposition will include a polymer backbone that includes cationicgroups.

For example, in one embodiment, the composition is formed by reacting anisocyanate-containing component with at least one amine-terminatedcomponent to form a polyurea. The isocyanate-containing component may bea monomer, e.g., a diisocyanate, or a prepolymer, e.g., the reactionproduct of an isocyanate-containing component and an amine-terminatedcomponent. The polyurea is then subjected to a post-polymerizationreaction with a neutralizing agent in which at least a portion of theamine groups in the backbone are alkylated, quaternized, or ternarized.

In another embodiment, a prepolymer formed from an isocyanate-containingcomponent and an amine-terminated component, at least one of whichincludes at least one precursor group of a cationic group or a cationicgroup, is chain extended with an amine-based curative. The amine-basedcurative may include a neutralizing agent.

Other variations of the invention include the use of curatives that havealready been neutralized, i.e., the curative includes cationic groups.

As used herein, the term “cationic group or precursor group thereof”means a group either already in cationic form or, by neutralization witha reagent, readily converted to the cationic form. Suitable precursorcationic groups (and neutralized cationic group form) are ≡N(≡N^(⊕)—),≡P(≡P^(⊕)—), and ═S(═S^(⊕)—).

The term “neutralize” as used herein for converting precursor groups toionic groups refers to alkylation, quaternarization, and ternarization.For example, the precursor cationic group may be quaternized orternarized as the case may be by neutralization or quaternarization ofthe tertiary amine, or reacting the phosphine or sulfide with compoundscapable of alkylating the phosphine or sulfide groups. As such, the term“neutralizing agent” as used herein refers to alkylating agents,quaternizing agents, ternarizing agents, or mixtures thereof. Suitableneutralizing agents include, but are not limited to, quaternizing agentshaving the formula QX, where Q may be hydrogen, benzyl, methyl, ethyl,and mixtures thereof and X may be a monovalent anion such as a halide(e.g., chloride, bromide, iodide, methyl sulfate, ethyl sulfate, H₂PO₄⁻, and acetate). For example, quaternizing agents suitable for use withthe present invention include, but are not limited to, dialkyl sulfatessuch as dimethyl sulfate, diethyl sulfate, and the like, alkyl halidessuch as methyl chloride, methyl bromide, and the like, benzyl halidessuch as benzyl chloride,N-(3-chloro-2-hydroxypropyl)-N,N,N-trimethylammonium chloride, glacialacetic acid, phosphoric acid, sodium chloroacetate, alkali metal saltsof chlorocarboxylic or bromocarboxylic acids, hydrocarbyl substitutedcarbonates, and mixtures thereof. A sulfide-acid mixture may be used asa ternarizing agent according to the invention.

The subscript letters such as n, x, and y as used herein within thegeneric structures are understood by one of ordinary skill in the art asthe degree of polymerization (i.e., the number of consecutivelyrepeating units). In the case of molecularly uniformed products, thesenumbers are commonly integers, if not zero. In the case of molecularlynon-uniformed products, these numbers are averaged numbers not limitedto integers, if not zero, and are understood to be the average degree ofpolymerization.

The various components of the composition are discussed below.

Isocyanate-Containing Component

The isocyanate-containing component may be in the form of a monomer orprepolymer. For example, as used herein, the term “isocyanate-containingcomponent” may be understood to encompass a monomer containing at leastone terminal isocyanate (NCO) group, as well as a prepolymer containingat least one terminal isocyanate group. In one embodiment, theisocyanate-containing component includes at least two isocyanate groups.

The isocyanate-containing component may be aromatic, aromatic-aliphatic,or aliphatic, which provide varying degrees of light stability. As usedherein, aromatic aliphatic compounds should be understood as thosecontaining an aromatic ring, wherein the isocyanate group is notdirectly bonded to the ring. Along a continum, an aromatic compositionis less light stable than an aromatic-aliphatic composition, which isless light stable than an aliphatic composition. For example, analiphatic composition made according to the invention includes onlysaturated components, i.e., components substantially free of unsaturatedcarbon-carbon bonds or aromatic groups, the use of which preventsyellowing over time. The term “saturated,” as used herein, refers tocompositions having saturated aliphatic and alicyclic polymer backbones,i.e., with no carbon-carbon double bonds. It is important to note,however, that aromatic compositions made according to the invention mayinclude light stabilizers to improve light stability. Thus, lightstability may be accomplished in a variety of ways for the purposes ofthis application.

Suitable isocyanate-containing components include diisocyanates havingthe generic structure: O═C═N—R—N═C═O, where R is preferably a straightchain or branched aliphatic group, a substituted straight chain orbranched aliphatic group, an aromatic group, a substituted aromaticgroup, or mixtures thereof. In one embodiment, R is a hydrocarbon moietycontaining from about 1 to 20 carbon atoms. The diisocyanate may alsocontain one or more cyclic groups. When multiple cyclic groups arepresent, linear and/or branched hydrocarbons containing from about 1 to10 carbon atoms can be present as spacers between the cyclic groups. Insome cases, the cyclic group(s) may be substituted at the 2-, 3-, and/or4-positions, respectively. Substituted groups may include, but are notlimited to, halogens, primary, secondary, or tertiary hydrocarbongroups, or a mixture thereof.

Examples of saturated (aliphatic) diisocyanates include, but are notlimited to, ethylene diisocyanate; propylene-1,2-diisocyanate;tetramethylene diisocyanate; tetramethylene-1,4-diisocyanate;1,6-hexamethylene diisocyanate (HDI); HDI biuret prepared from HDI;octamethylene diisocyanate; decamethylene diisocyanate;2,2,4-trimethylhexamethylene diisocyanate; 2,4,4-trimethylhexamethylenediisocyanate; dodecane-1,12-diisocyanate; cyclobutane-1,3-diisocyanate;cyclohexane-1,2-diisocyanate; cyclohexane-1,3-diisocyanate;cyclohexane-1,4-diisocyanate; methylcyclohexylene diisocyanate (HTDI);2,4-methylcyclohexane diisocyanate; 2,6-methylcyclohexane diisocyanate;4,4′-dicyclohexyl diisocyanate; 2,4′-dicyclohexyl diisocyanate;1,3,5-cyclohexane triisocyanate; isocyanatomethylcyclohexane isocyanate;1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane;isocyanatoethylcyclohexane isocyanate; bis(isocyanatomethyl)-cyclohexanediisocyanate; 4,4′-bis(isocyanatomethyl)dicyclohexane;2,4′-bis(isocyanatomethyl)dicyclohexane; isophorone diisocyanate (IPDI);triisocyanate of HDI; triisocyanate of 2,2,4-trimethyl-1,6-hexanediisocyanate (TMDI); 4,4′-dicyclohexylmethane diisocyanate (H₁₂MDI);2,4-hexahydrotoluene diisocyanate; 2,6-hexahydrotoluene diisocyanate;aromatic aliphatic isocyanate, such as 1,2-, 1,3-, and 1,4-xylenediisocyanate; meta-tetramethylxylene diisocyanate (m-TMXDI);para-tetramethylxylene diisocyanate (p-TMXDI); trimerized isocyanurateof any polyisocyanate, such as isocyanurate of toluene diisocyanate,trimer of diphenylmethane diisocyanate, trimer of tetramethylxylenediisocyanate, isocyanurate of hexamethylene diisocyanate, isocyanurateof isophorone diisocyanate, and mixtures thereof; dimerized uretdione ofany polyisocyanate, such as uretdione of toluene diisocyanate, uretdioneof hexamethylene diisocyanate, and mixtures thereof; modifiedpolyisocyanate derived from the above isocyanates and polyisocyanates;and mixtures thereof. In one embodiment, the saturated diisocyanatesinclude isophoronediisocyanate (IPDI), 4,4′-dicyclohexylmethanediisocyanate (H₁₂MDI), 1,6-hexamethylene diisocyanate (HDI), or acombination thereof.

As briefly discussed, aromatic aliphatic isocyanates may also be used asthe isocyanate-containing component. While use of aromatic aliphaticmaterials does not confer the same amount of light stability to theresultant product compared to those including purely aliphaticmaterials, it does provide a greater degree of light stability to theresultant product compared to those formed with purely aromaticmaterials. Examples of aromatic aliphatic isocyanates include 1,2-,1,3-, and 1,4-xylene diisocyanate; meta-tetramethylxylene diisocyanate(m-TMXDI); para-tetramethylxylene diisocyanate (p-TMXDI); trimerizedisocyanurate of any polyisocyanate, such as isocyanurate of toluenediisocyanate, trimer of diphenylmethane diisocyanate, trimer oftetramethylxylene diisocyanate, isocyanurate of hexamethylenediisocyanate, and mixtures thereof; dimerized uretdione of anypolyisocyanate, such as uretdione of toluene diisocyanate, uretdione ofhexamethylene diisocyanate, and mixtures thereof; a modifiedpolyisocyanate derived from the above isocyanates and polyisocyanates;and mixtures thereof. In addition, the aromatic aliphatic isocyanatesmay be mixed with any of the saturated isocyanates listed above for thepurposes of this invention.

Unsaturated diisocyanates, i.e., aromatic compounds, may also be used asthe isocyanate-containing component, although the use of unsaturatedcompounds in the precursor is preferably coupled with the use of a lightstabilizer or pigment as discussed below. Examples of unsaturateddiisocyanates include, but are not limited to, substituted and isomericmixtures including 2,2′-, 2,4′-, and 4,4′-diphenylmethane diisocyanate(MDI), 3,3′-dimethyl-4,4′-biphenyl diisocyanate (TODI), toluenediisocyanate (TDI), polymeric MDI (PMDI, a brown liquid composed ofapproximately 50% methylene diisocyanate with the remainder comprised ofoligomers of MDI), carbodiimide-modified liquid 4,4′-diphenylmethanediisocyanate, para-phenylene diisocyanate (PPDI), meta-phenylenediisocyanate (MPDI), triphenylmethane-4,4′-, andtriphenylmethane-4,4′-triisocyanate, napthylene-1,5,-diisocyanate,2,4′-, 4,4′-, and 2,2′-biphenyl diisocyanate, polyphenylenepolymethylene polyisocyanate (PMDI) (also known as polymeric PMDI), andmixtures thereof.

The isocyanate-containing component itself may be covalentlyincorporated or functionalized with cationic group or precursor groupthereof. In one embodiment, the isocyanate-containing component isfunctionalized with at least one precursor cationic group such as ≡N,≡P, ═S, and mixtures thereof. In another embodiment, theisocyanate-containing component is functionalized with at least oneneutralized cationic group including, but not limited to, ≡N^(⊕)—,≡P^(⊕)—, ═S^(⊕)—, and mixtures thereof.

Those of ordinary skill in the art would be aware of suitable methods ofincorporating at least one cationic group or precursor group thereof tothe isocyanate-containing component. For example, tertiary amines,phosphines, sulfides, and the like may be incorporated into theisocyanate-containing component. Suitable compounds for use in thisaspect of the invention include, but are not limited to,methyldiethanolamine (hydrochloride salt, acetic acid salt),N,N-di(2-hydroxypropyl)aniline (hydrochloride salt, acetic acid salt),N-cyclohexyl-N-(3-aminopropyl)propanol-2-amine (hydrochloride salt,acetic acid salt), ethyldiethanolamine (hydrochloride salt, acetic acidsalt), glycerol-α-bromohydrin quaternized with tributylamine (ammoniumsalt), triethyl phosphine (phosphonium salt), glycerol-α-bromohydrinternarized with dimethyl sulfide (sulfonium salt), and mixtures thereof.

Likewise, those of ordinary skill in the art would be aware of methodsto neutralize the cationic precursor group. In fact, the synthesis of aquaternary ammonium salt should be known to those of ordinary skill inthe art. For example, an amine can react with an alkyl halide, producingan amine of the next higher class, wherein one of the hydrogens attachedto nitrogen has been replaced by an alkyl group, which eventuallyproduces an ammonium salt. The general reaction scheme is demonstratedbelow:

Any or all of the R groups may be the same or different substituted orunsubstituted alkyl groups. Also, any of the R groups may be connected.X⁻ may be any one of fluoride, chloride, bromide, iodide, hydroxide,carbonate, and mixtures thereof.

A quaternary ammonium salt, contemplated by the inventors as a suitablecationic group according to the present invention, has the followinggeneral formula:

R and X⁻ are as defined above.

The functionalized isocyanate-containing component may be neutralizedprior to, during, or after polymerization. In this aspect of theinvention, the isocyanate-containing component may include at least onequaternized tertiary amine, alkylated phosphine group, alkylated sulfidegroup, or a mixture thereof prior to reaction with anyisocyanate-reactive components. In an alternate embodiment, theisocyanate-containing component includes at least one cationic precursorgroup that may later be neutralized.

In another embodiment, the isocyanate-containing component includes atleast one quaternizing or ternarizing moiety that can later, e.g.,prior, during, or after polymerization, be reacted with a separatereagent that includes a precursor phosphine or sulfide group to form thecationic groups in the polymer.

Regardless of when it is introduced (e.g., prior to, during, or afterpolymerization), the neutralizing agent is preferably added in an amountsufficient to react with at least about 10 percent of the potentialcationic groups. In one embodiment, the neutralizing agent is added inan amount sufficient to react with at least about 20 percent of thepotential cationic groups. In another embodiment, the neutralizing agentis added in an amount sufficient to react with between about 20 percentand 60 percent of the potential cationic groups. A flow modifier mayincrease the reaction between the neutralizing agent and the potentialcationic groups. As such, in one embodiment, the neutralizing agent anda flow modifier are used to achieve conversion of greater than about 60percent, preferably at least about 75 percent, and more preferably about90 percent or more of the potential cationic groups to cationic groups.

Isocyanate-Reactive Component

Whether forming a prepolymer or chain extending the prepolymer with anamine-terminated component, the isocyanate groups in theisocyanate-containing component react with the amine groups of theisocyanate-reactive component (also referred to herein asamine-terminated component) to form a repeating urea linkage, which hasthe following general structure:

where x is the number of repeat units, i.e., about 1 or greater, and Rand R₁ independently include straight chain or branched aliphaticgroups, substituted straight chain or branched aliphatic groups,aromatic groups, substituted aromatic groups, or mixtures thereof.

Any amine-terminated component available to one of ordinary skill in theart is suitable for use in the compositions of the invention. Forexample, the amine-terminated prepolymer component may includeamine-terminated hydrocarbons including amine-terminated polyolefins,amine-terminated polyethers, amine-terminated polyesters includingamine-terminated polycaprolactones, amine-terminated polycarbonates,amine-terminated polyamides including amine-terminated polycaprolactams,amine-terminated polyacrylates, amine-terminated polysiloxanes,amine-terminated polyimines, amine-terminated polyimides, and mixturesthereof. U.S. Pat. No. 6,958,379, which is incorporated by referenceherein, discloses suitable amine-terminated compounds for use with thepresent invention.

In addition, the amine-terminated component may be a copolymer of any ofthe amine-terminated components listed above. For example, in oneembodiment, the amine-terminated component includes amine-terminatedpolyolefinsiloxanes (such as α,ω)-diaminopoly(butadiene-dimethylsiloxane) and α,ω-diaminopoly(isobutylene-dimethylsiloxane)), amine-terminated polyetherolefins(such as α,ω-diamino poly(butadiene-oxyethylene)), amine-terminatedpolyetheresters, amine-terminated polyethercarbonates, amine-terminatedpolyetheramides, amine-terminated polyetheracrylates, amine-terminatedpolyethersiloxanes, amine-terminated polyesterolefins (such asα,ω)-diamino poly(butadiene-caprolactone) and α,ω-diaminopoly(isobutylene-caprolactone)), amine-terminated polyesteramides,amine-terminated polyestercarbonates, amine-terminatedpolyesteracrylates, amine-terminated polyestersiloxanes,amine-terminated polyamideolefins, amine-terminated polyamidecarbonates,amine-terminated polyamideacrylates, amine-terminatedpolyamidesiloxanes, amine-terminated polyamideimides, amine-terminatedpolycarbonateolefins, amine-terminated polycarbonateacrylates,amine-terminated polycarbonatesiloxanes, amine-terminatedpolyacrylateolefins (such as α,ω-diamino poly(butadiene-methylmethacrylate), α,ω-diamino poly(isobutylene-t-butyl methacrylate), andα,ω-diamino poly(methyl methacrylate-butadiene-methyl methacrylate)),amine-terminated polyacrylatesiloxanes, amine-terminatedpolyetheresteramides, and combinations thereof. U.S. Pat. No. 7,098,274,incorporated by reference in its entirety herein, discloses morespecific examples of amine-terminated components suitable for use withthe present invention.

The amine-terminated component may be in the form of a primary amine(R₁—NH₂), a secondary amine (R₁—NHR₂), tertiary amine (R₁—NR₂R₃), ormixtures thereof. As such, the amine-terminated component includes thefollowing generic structures:H₂N—R₁—NH₂;R₂HN—R₁—NHR₂;R₃R₂N—R₁—NR₂R₃;H₂N—R₁—NHR₂;R₃R₂N—R₁—NH₂; orR₃R₂N—R₁—NHR₂where R₁ may be an unsubstituted or substituted straight chain orbranched aliphatic groups, unsubstituted or substituted aromatic groups,or mixtures thereof and R₂ and R₃ may independently be an alkyl, aryl,or aralkyl group.

The present invention also contemplates the use of triamines withsimilar generic structures:

where R₁′ and R₁″ may independently be an unsubstituted or substitutedstraight chain or branched aliphatic groups, unsubstituted orsubstituted aromatic groups, or mixtures thereof and R₂ and R₃ mayindependently be an alkyl, aryl, or aralkyl group.

The molecular weight of the amine-terminated component for use in theinvention may range from about 100 to about 10,000. In one embodiment,the amine-terminated component is about 500 or greater, preferably about1000 or greater, and even more preferably about 2000 or greater. Inanother embodiment, the amine-terminated component molecular weight isabout 8000 or less, preferably about 4,000 or less, and more preferablyabout 3,000 or less. For example, in one embodiment, the molecularweight of the amine-terminated component is about 1000 to about 4000.

The amine-terminated component itself may be covalently incorporated orfunctionalized with cationic group or precursor group thereof. Similarmethods as discussed above with respect to suitable methods forfunctionalizing the isocyanate-containing component with a cationicgroup or a precursor group thereof may be employed to functionalize anamine-terminated component according to the present invention. Forexample, because, in general, tertiary amino groups may be quaternizedor ternarized, no additional functional groups need be added to theamine-terminated component if the amine-terminated component itselfincludes at least one terminal tertiary amine group.

The amine-terminated component may be functionalized with at least onetertiary amine group (≡N), phosphine group (≡P), or sulfide group (═S).For example, a primary or secondary diamine with at least one tertiaryamine group may be used as the amine-terminated component of theinvention. In another embodiment, a primary or secondary triamine withat least one tertiary amine group may be used as the amine-terminatedcomponent. Alternatively, a quaternizing or ternarizing moiety may beadded to the amine-terminated component and later reacted with aseparate reagent that includes phosphine or sulfide.

In one embodiment, the amine-terminated component of the presentinvention is a primary or secondary diamine with one or more precursorcationic groups. In another embodiment, the amine-terminated componentof the present invention is a primary or secondary triamine with one ormore precursor cationic groups. The precursor cationic groups may beneutralized prior to reaction with the isocyanate-containing component.For example, the amine-terminated component may include at least oneneutralized cationic group including, but not limited to, ≡N^(⊕)—,≡P^(⊕)—, ═S^(⊕)—, and mixtures thereof, prior to polymerization with theisocyanate-containing component. In the alternative, theamine-termination component may be neutralized during or afterpolymerization with the isocyanate-containing component.

The cationic or precursor cationic groups preferably account for about 1percent to about 50 percent of the weight of the amine-terminatedcomponent. In one embodiment, the cationic or precursor cationic groupsconstitute about 3 percent to about 45 percent of the weight of theamine-terminated component. In another embodiment, the cationic orprecursor cationic groups account for about 5 percent to about 35percent of the weight of the amine-terminated component. In stillanother embodiment, the cationic or precursor cationic groups constituteabout 5 percent to about 25 percent of the weight of theamine-terminated component. And, when included in theisocyanate-containing component and/or curative, the cationic orprecursor cationic groups preferably account for about the same rangesof the weight of the component.

Amine-Based Curative

As generally understood by those of ordinary skill in the art, theprocess of making polyurea compositions generally includes formation ofa prepolymer with a relatively long chain (high molecular weight)amine-terminated component to produce a prepolymer containing freeisocyanate groups that is then chain extended with a short chain (lowmolecular weight) amine-terminated curing agent to form a polyurea. Thelong chain, high molecular weight amine-terminated component providesflexibility and elastomeric properties to the resin, while the shortchain amine-terminated curing agent provides chain extension orcross-links and adds toughness and rigidity to the resulting elastomericpolymer. Thus, any of the amine-terminated moieties listed above for useas the isocyanate-reactive amine-terminated component may be used ascuring agents to react with a prepolymer or the isocyanate-containingcomponent may be directly reacted with the amine-based curative to formthe polymer. However, the amine-terminated curing agent preferably has amolecular weight of about 64 or greater. In one embodiment, themolecular weight of the amine-curing agent is about 2000 or less.

As such, like the isocyanate-containing component and theisocyanate-reactive component above, the curative may be a source ofcationic or precursor cationic groups to achieve the present invention.For example, the amine-based curative may include an amine-terminatedcuring agent that does not include a cationic or precursor cationicgroup, a neutralizing agent, and optional flow modifier. In an alternateembodiment, the amine-based curative itself includes at least oneprecursor cationic group, a neutralizing agent, and an optional flowmodifier. In still another embodiment, the amine-based curative includesat least one cationic or precursor cationic group, however, theneutralizing agent is present in the prepolymer, added separately duringcure, or is added post-polymerization.

The curative may include a single amine-terminated curing agent or amixture of amine-terminated curing agents. In one embodiment, theamine-terminated curing agent is an of the one of the following:ethylene diamine; hexamethylene diamine; 1-methyl-2,6-cyclohexyldiamine; 2,2,4- and 2,4,4-trimethyl-1,6-hexanediamine;4,4′-bis-(sec-butylamino)-dicyclohexylmethane and derivatives thereof;1,4-bis-(sec-butylamino)-cyclohexane;1,2-bis-(sec-butylamino)-cyclohexane; 4,4′-dicyclohexylmethane diamine;1,4-cyclohexane-bis-(methylamine); 1,3-cyclohexane-bis-(methylamine),isomers, and mixtures thereof; diethylene glycol bis-(aminopropyl)ether;2-methylpentamethylene-diamine; diaminocyclohexane, isomers, andmixtures thereof; diethylene triamine; triethylene tetramine;tetraethylene pentamine; propylene diamine; 1,3-diaminopropane;dimethylamino propylamine; diethylamino propylamine;imido-bis-(propylamine); monoethanolamine, diethanolamine;triethanolamine; monoisopropanolamine, diisopropanolamine;isophoronediamine; 4,4′-methylenebis-(2-chloroaniline);3,5-dimethylthio-2,4-toluenediamine;3,5-dimethylthio-2,6-toluenediamine; 3,5-diethylthio-2,4-toluenediamine;3,5-diethylthio-2,6-toluenediamine; 3,5-diethyltoluene-2,4-diamine;3,5-diethyltoluene-2,6-diamine; 4,4′-bis-(sec-butylamino)-benzene; andderivatives thereof; 1,4-bis-(sec-butylamino)-benzene;1,2-bis-(sec-butylamino)-benzene; N,N′-dialkylamino-diphenylmethane;trimethyleneglycol-di-p-aminobenzoate;polytetramethyleneoxide-di-p-aminobenzoate;4,4′-methylenebis-(3-chloro-2,6-diethyleneaniline);4,4′-methylenebis-(2,6-diethylaniline); meta-phenylenediamine;paraphenylenediamine; N,N′-diisopropyl-isophoronediamine;polyoxypropylene diamine; propylene oxide-based triamine;3,3′-dimethyl-4,4′-ciaminocyclohexylmethane; and mixtures thereof. Inone embodiment, the amine-terminated curing agent is4,4′-bis-(sec-butylamino)-dicyclohexylmethane.

Of the list above, the saturated amine-terminated curing agents suitablefor use with the present invention include, but are not limited to,ethylene diamine; hexamethylene diamine; 1-methyl-2,6-cyclohexyldiamine; 2,2,4- and 2,4,4-trimethyl-1,6-hexanediamine;4,4′-bis-(sec-butylamino)-dicyclohexylmethane;1,4-bis-(sec-butylamino)-cyclohexane;1,2-bis-(sec-butylamino-cyclohexane; derivatives of4,4′-bis-(sec-butylamino)-dicyclohexylmethane; 4,4′-dicyclohexylmethanediamine; 1,4-cyclohexane-bis-(methylamine);1,3-cyclohexane-bis-(methylamine); diethylene glycol bis-(aminopropyl)ether; 2-methylpentamethylene-diamine; diaminocyclohexane; diethylenetriamine; triethylene tetramine; tetraethylene pentamine; propylenediamine; dipropylene triamine; 1,3-diaminopropane; dimethylaminopropylamine; diethylamino propylamine; imido-bis-(propylamine);monoethanolamine, diethanolamine; triethanolamine; monoisopropanolamine,diisopropanolamine; triisopropanolamine; isophoronediamine;N,N′-diisopropylisophorone diamine and mixtures thereof.

In one embodiment, the curative used with the prepolymer include3,5-dimethylthio-2,4-toluenediamine,3,5-dimethyl-thio-2,6-toluenediamine,4,4′-bis-(sec-butylamino)-diphenylmethane, N,N′-diisopropyl-isophoronediamine; polyoxypropylene diamine; propylene oxide-based triamine;3,3′-dimethyl-4,4′-diaminocyclohexylmethane; and mixtures thereof.

However, it should be understood that the curing agent may also be anyof the above components in a form that includes cationic or precursorcationic groups, especially when neither the isocyanate-containingcomponent nor the isocyanate-reactive component used to form theprepolymer contains such groups.

Because unhindered primary diamines result in a rapid reaction betweenthe isocyanate groups and the amine groups, in certain instances, ahindered secondary diamine may be more suitable for use in theprepolymer. Without being bound to any particular theory, it is believedthat an amine with a high level of stearic hindrance, e.g., a tertiarybutyl group on the nitrogen atom, has a slower reaction rate than anamine with no hindrance or a low level of hindrance. For example,4,4′-bis-(sec-butylamino)-dicyclohexylmethane (Clearlink® 1000) may besuitable for use in combination with an isocyanate to form the polyureaprepolymer. In addition, N,N′-diisopropyl-isophorone diamine, availablefrom Huntsman Corporation under the tradename Jefflink, may be used asthe secondary diamine curing agent.

In addition, a trifunctional curing agent can be used to help improvecross-linking and, thus, to further improve the shear resistance of theresulting polyurea elastomers. In one embodiment, a triol such astrimethylolpropane or a tetraol such as N,N,N′,N′-tetrakis(2-hydroxylpropyl)ethylenediamine may be added to the formulations.

As discussed, the amine-based curative may include a neutralizing agent.Suitable neutralizing agents include, but are not limited to, any of thealkylating agents, quaternizing agents, ternarizing agents, or mixturesthereof previously discussed.

In another embodiment, the curative includes a flow modifier. Suitableflow modifiers include, but are not limited to, aliphatic, mono- ormulti-functional (saturated, unsaturated, or multi-unsaturated) organicacids and salts thereof. In one embodiment, the organic acids arepreferably saturated or unsaturated fatty acids or fatty acid salts.Suitable fatty acids include, but are not limited to, stearic acid,behenic acid, erucic acid, oleic acid, linoelic acid, myristic acid,palmitic acid, decanoic acid, or dimerized derivatives.

For example, saturated fatty acids such as butyric acid, caproic acid,caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid,stearic acid, arachidic acid, behenic acid, lignoceric acid, and thelike are contemplated for use as a flow modifier according to thepresent invention. Unsaturated fatty acids suitable for use as the flowmodifier of the present invention include, but are not limited to,myristoleic acid, palmitoleic acid, oleic acid, linoleic acid,α-linolenic acid, arachidonic acid, eicosapentaenoic acid, erucic acid,and docosahexaenoic acid.

Suitable salts of fatty acids for use in accordance with the presentinvention, which may be formed by replacing one or more of the hydrogenatoms of the acid with an anion or cation, include, but are not limitedto, barium salts, lithium salts, sodium salts, zinc salts, bismuthsalts, chromium salts, cobalt salts, copper salts, potassium salts,strontium salts, titanium salts such as 2-ethylhexyl titanate, tungstensalts, magnesium salts, cesium salts, iron salts, nickel salts, silversalts, aluminum salts, tin salts, calcium salts of fatty acids.

For example, barium, lithium, sodium, zinc, bismuth, chromium, cobalt,copper, potassium, strontium, titanium, tungsten, magnesium, cesium,iron, nickel, silver, aluminum, tin, or calcium salts of stearic,behenic, erucic, oleic, linoelic or dimerized derivatives thereof arecontemplated for use as the flow modifier in accordance with the presentinvention. In one embodiment, the flow modifier includes at least one ofzinc stearate, magnesium stearate, calcium stearate, magnesium12-hydroxystearate, calcium 12-hydroxystearate, zinc 12-hydroxystearate,magnesium arachidate, calcium arachidate, zinc arachidate, magnesiumbehenate, calcium behenate, zinc behenate, magnesium lignocerate,calcium lignocerate, zinc lignocerate, or mixtures thereof. In anotherembodiment, the flow modifier is zinc stearate.

Method of Forming the Composition

As discussed above, there are several methods for forming thecompositions of the invention. Precursor groups of cationic groups maybe incorporated into the isocyanate-containing component, theisocyanate-reactive component, or curative before, during, or after theprepolymer formation or the curing reaction. They can be neutralized tocorresponding cationic groups before, during, or after prepolymerformation or the curing reaction. For example, cationic precursor groupssuch as tertiary amine, phosphine, and sulfide groups can be neutralizedby quaternization of the tertiary amine, or by reacting the phosphine orsulfide with compounds capable of alkylating the phosphine or sulfidegroups.

The polyurea compositions of the invention may be prepared using theone-shot process, i.e., the reactants above are added simultaneouslyunder polymerization conditions. In this type of process, theisocyanate-containing component and the amine-terminated prepolymercomponent and/or curative may be combined under polymerizationconditions to form the product. Any or all of these components mayinclude the precursor cationic groups or cationic groups. If theresulting polymer includes precursor cationic groups, the polymer may besubjected to a neutralizing agent in a post-polymerization reaction.Alternatively, the component containing the precursor cationic group maybe neutralized prior to polymerization.

In addition, the polyurea compositions of the invention may be formedusing a prepolymer method, i.e., a prepolymer with excess isocyanategroups is chain extended with a curative. While both types of processesare contemplated for use with the present invention, the prepolymermethod affords greater control over the reaction process. For example,in one embodiment, an isocyanate-containing component and anamine-terminated component with at least one precursor cationic group isreacted to form a polyurea prepolymer that is then chain extended withan amine-based curative that includes a neutralizing agent and anoptional flow modifier. The amine-terminated component may beneutralized before reaction to form the prepolymer, during reaction toform the prepolymer, during the cure stage, or post-polymerization.

The content of reactable isocyanate moieties in the polyurea prepolymer,expressed as percent NCO by weight, may be manipulated to control suchfactors as curing rate, hardness of the resulting material, and thelike. All else being the same, the hardness of the resulting materialcan increase as the percent NCO of the prepolymer increases. The percentNCO by weight in the prepolymer may be less than about 15 percent, lessthan about 11 percent, less than about 9 percent, less than about 7percent, or even less, or at least about 2 percent, such as about 3percent or about 4 percent or greater, or any percentage therebetween,such as about 5 to 11 percent, about 6 to 10 percent, about 3 to 9percent, about 2.5 to 7.5 percent, or about 4 to 6.8 percent.Prepolymers with higher percent NCO (e.g., 14 percent or higher) can beconverted to prepolymers with lower percent NCO (e.g., 10 percent) byfurther reacting with one or more other isocyanate-reactive components.

When the prepolymer includes precursor cationic groups or cationicgroups, the cationic groups comprise between about 1 to about 50 percentby weight of the prepolymer. In one embodiment, the prepolymer includesbetween about 5 percent to about 45 percent cationic groups by weight ofthe prepolymer. In another embodiment, the prepolymer includes betweenabout 10 percent and about 35 percent cationic groups by weight of theprepolymer. In yet another embodiment, between about 5 weight percentand 25 weight percent cationic groups are present in the prepolymer.

When the curing agent includes precursor cationic groups or cationicgroups, the cationic groups comprise between about 1 to about 50 percentby weight of the curing agent. In one embodiment, the curing agentincludes between about 5 percent to about 45 percent cationic groups byweight of the curing agent. In another embodiment, the curing agentincludes between about 10 percent and about 35 percent cationic groupsby weight of the curing agent. In yet another embodiment, between about5 weight percent and 25 weight percent cationic groups are present inthe curing agent.

With respect to the neutralization, quaternarization or ternarizationstep, whatever the case may be, the neutralizing agent may be added in asufficient amount to react with at least about 10 percent of thepotential cationic groups or moieties in the polymer. In one embodiment,the neutralizing agent is added in an amount sufficient to react withbetween about 10 percent and 70 percent, between about 20 percent toabout 60 percent, between about 30 percent to about 70 percent, or thelike, of the potential cationic moieties.

The percent of neutralization may increase with the addition of a flowmodifier. As such, the use of a flow modifier either in the amine-basedcurative or in a blend with a neutralizing agent if apost-polymerization reaction is used is contemplated by the presentinvention. Any of the flow modifiers listed above for possible inclusionin the amine-based curative is suitable for use in this aspect of theinvention. A skilled artisan would be aware that the flow modifier ispreferably selected such that the molecular weight is much less than theacid-containing component, e.g., about 200 or greater, about 2000 orless, or somewhere in between. The small molecular weight of the flowmodifier allows proper adjustment of the melt flow index of theresulting composition.

In this aspect of the invention, the flow modifier is added in an amountof about 15 parts per hundred (pph) to about 75 pph based on a hundredparts of the acid-containing component. In one embodiment, the flowmodifier is added in an amount of about 20 pph to about 70 pph. Inanother embodiment, the flow modifier is present in an amount of about25 pph to about 50 pph. In yet another embodiment, the flow modifier isadded in an amount of about 25 pph to about 75 pph.

With the flow modifier, the precursor cationic moieties are neutralizedgreater than about 70 percent. In one embodiment, the neutralizationlevel is about 80 percent or greater. In another embodiment, theneutralization level is about 90 percent or higher. In yet anotherembodiment, the acid moieties are fully neutralized, i.e., all of theacid moieties (100 percent) are neutralized.

In addition to the general reaction chemistry, the actual process offorming the composition may differ based on the desired final product.For example, the ratio of isocyanate groups and amino groups determinewhether the final product is thermoplastic or thermoset, each of whichis contemplated for use with the present invention. In one embodiment,the ratio of NCO groups on the isocyanate-containing component to activehydrogen groups on the amine-terminated prepolymer component andamine-based curative is between about 1:0.7 and about 1:1.3. Forexample, those of ordinary skill in the art will be aware that a ratiobetween about 1:0.9 and about 0.9:1, more preferably between about1:0.95 and about 0.95:1, will produce a thermoset product. In contrast,a ratio of about 1:1 NCO groups to active hydrogen groups will result ina thermoplastic product.

In one embodiment, the compositions of the invention are thermoplasticin nature. In another embodiment, the compositions of the invention arethermoset.

Additives

The compositions of the invention may include a variety of additives.For example, the compositions of the invention may be foamed by theaddition of the at least one physical or chemical blowing or foamingagent. The use of a foamed polymer allows the golf ball designer toadjust the density or mass distribution of the ball to adjust theangular moment of inertia, and, thus, the spin rate and performance ofthe ball. Foamed materials also offer a potential cost savings due tothe reduced use of polymeric material.

Blowing or foaming agents useful include, but are not limited to,organic blowing agents, such as azobisformamide; azobisisobutyronitrile;diazoaminobenzene; N,N-dimethyl-N,N-dinitroso terephthalamide;N,N-dinitrosopentamethylene-tetramine; benzenesulfonyl-hydrazide;benzene-1,3-disulfonyl hydrazide; diphenylsulfon-3-3, disulfonylhydrazide; 4,4′-oxybis benzene sulfonyl hydrazide; p-toluene sulfonylsemicarbizide; barium azodicarboxylate; butylamine nitrile; nitroureas;trihydrazino triazine; phenyl-methyl-uranthan; p-sulfonhydrazide;peroxides; and inorganic blowing agents such as ammonium bicarbonate andsodium bicarbonate. A gas, such as air, nitrogen, carbon dioxide, etc.,can also be injected into the composition during the injection moldingprocess.

Additionally, a foamed composition of the present invention may beformed by blending microspheres with the composition either during orbefore the molding process. Polymeric, ceramic, metal, and glassmicrospheres are useful in the invention, and may be solid or hollow andfilled or unfilled. In particular, microspheres up to about 1000micrometers in diameter are useful. Furthermore, the use of liquidnitrogen for foaming, as disclosed in U.S. Pat. No. 6,386,992, which isincorporated by reference herein, may produce highly uniform foamedcompositions for use in the present invention.

Fillers may also be added to the compositions of the invention to affecttheological and mixing properties, the specific gravity (i.e.,density-modifying fillers), the modulus, the tear strength,reinforcement, and the like. The fillers are generally inorganic, andsuitable fillers include numerous metals, metal oxides and salts, suchas zinc oxide and tin oxide, as well as barium sulfate, zinc sulfate,calcium carbonate, zinc carbonate, barium carbonate, clay, tungsten,tungsten carbide, an array of silicas, regrind (recycled core materialtypically ground to about 30 mesh particle), high-Mooney-viscosityrubber regrind, and mixtures thereof.

For example, the compositions of the invention can be reinforced byblending with a wide range of density-adjusting fillers, e.g., ceramics,glass spheres (solid or hollow, and filled or unfilled), and fibers,inorganic particles, and metal particles, such as metal flakes, metallicpowders, oxides, and derivatives thereof, as is known to those withskill in the art. The selection of such filler(s) is dependent upon thetype of golf ball desired, i.e., one-piece, two-piece, multi-component,or wound, as will be more fully detailed below. Generally, the fillerwill be inorganic, having a density of greater than 4 g/cc, and will bepresent in amounts between about 5 and about 65 weight percent based onthe total weight of the polymer components included in the layer(s) inquestion. Examples of useful fillers include zinc oxide, barium sulfate,calcium oxide, calcium carbonate, and silica, as well as other knowncorresponding salts and oxides thereof.

When the compositions of the invention are used in the core layers ofthe golf ball, fillers may also be used to modify the weight of the coreto create a specialty ball, e.g., a lower weight ball is preferred for aplayer having a low swing speed.

Additional materials conventionally included in other golf ballcompositions may also be included in the compositions of the invention.For example, antioxidants, stabilizers, softening agents, plasticizers,including internal and external plasticizers, reinforcing materials, andcompatibilizers may also be added to any composition of the invention.Those of ordinary skill in the art are aware of the purpose of theseadditives and the amounts that should be employed to fulfill thosepurposes.

Blends

The compositions of the present invention may also be blended with otherpolymers. In particular, the compositions of the invention preferablyinclude about 1 percent to about 100 percent of the polyurea product. Inone embodiment, the compositions contain about 10 percent to about 90percent of the polyurea product, preferably from about 10 percent toabout 75 percent of the polyurea product, and about 90 percent to 10percent, more preferably from about 90 percent to about 25 percent ofthe second polymer component and/or other materials as described below.For example, a blend in accordance in the present invention may haveabout 10 percent to about 40 percent of the polyurea product and about60 percent to about 90 percent of another thermoplastic polymer, e.g., aconventional ionomer. In an alternate embodiment, a blend in accordancewith the invention may include about 40 percent to about 80 percent ofthe polyurea product and about 20 percent to about 60 percent of anotherthermoplastic polymer. Unless otherwise stated herein, all percentagesare given in percent by weight of the total composition of the golf balllayer in question.

For example, the compositions of the invention may be present in a blendwith ionomeric copolymers or terpolymers, ionomeric precursors,thermoplastics, polyamides, polycarbonates, polyesters, polyurethanes,polyureas, thermoplastic elastomers, polybutadiene rubber, balata,grafted and non-grafted metallocene-catalyzed polymers, single-sitepolymers, high-crystalline acid polymers, cationic polymers, cationicand anionic urethane ionomers and urethane epoxies, polyurethaneionomers, polyurea ionomers, epoxy resins, polyethylenes, polyacrylin,siloxanes, and mixtures thereof.

Examples of suitable urethane ionomers are disclosed in U.S. Pat. No.5,692,974, the disclosure of which is hereby incorporated by referencein its entirety. Other examples of suitable polyurethanes are describedin U.S. Pat. No. 5,334,673, the entire disclosure of which isincorporated by reference herein. Examples of suitable polyureas used toform the polyurea ionomer listed above are discussed in U.S. Pat. No.5,484,870. In particular, the polyureas of U.S. Pat. No. 5,484,870 areprepared by reacting a polyisocyanate and a polyamine curing agent toyield polyurea, which are distinct from the polyureas of the presentinvention that are formed from a polyurea prepolymer and curing agent.Examples of suitable polyurethanes cured with epoxy group containingcuring agents are disclosed in U.S. Pat. No. 5,908,358. The disclosuresof the above patents are incorporated herein by reference in theirentirety.

One of ordinary skill in the art would be well aware of methods to blendthese polymeric materials with the organically modified silicate of theinvention to form a composition for use in golf ball layers.

Golf Ball Construction

As discussed briefly above, the compositions of the present inventionmay be used with any type of ball construction including, but notlimited to, one-piece, two-piece, three-piece, and four-piece designs, adouble core, a double cover, an intermediate layer(s), a multilayercore, and/or a multi-layer cover depending on the type of performancedesired of the ball. That is, the compositions of the invention may beused in a core, an intermediate layer, and/or a cover of a golf ball,each of which may have a single layer or multiple layers. In oneembodiment, the compositions of the invention are used as a cover layerin a golf ball.

As used herein, the term “multilayer” means at least two layers. Forinstance, the core may be a one-piece core or a multilayer core, i.e., acore that has an innermost component with an additional core layer oradditional core layers disposed thereon. As used herein, the terms“core” and “center” are generally used interchangeably to reference theinnermost component of the ball. In some embodiments, however, the term“center” is used when there are multiple core layers, i.e., a center andan outer core layer.

When the golf ball of the present invention includes an intermediatelayer, which may also include more than one layer, this layer may beincorporated with a single or multilayer cover, a single or multi-piececore, with both a single layer cover and core, or with both a multilayercover and a multilayer core. The intermediate layer may be also bereferred to as an inner cover layer or outer core layer, or any otherlayer(s) disposed between the inner core and the outer cover of a golfball.

Referring to FIG. 1, a golf ball 2 of the present invention can includea center 4 and a cover 6 surrounding the center 4. While dimensions andmaterials are discussed in more detail below, a golf ball of theinvention can include a large core, e.g., about 1.55 inches to about1.60 inches, and a relatively soft, thin cover formed from thecomposition of the invention. In particular, the cover may have athickness of about 0.02 inches to about 0.07 inches, preferably about0.02 inches to about 0.045 inches, and more preferably about 0.025inches to about 0.035 inches.

Referring to FIG. 2, a golf ball 8 of the present invention can includea center 10, a cover 14, and at least one intermediate layer 12 disposedbetween the cover and the center. In one embodiment, the cover 14 isformed from the composition of the invention. In another embodiment, theintermediate layer 12 is formed from the composition of the invention.Each of the cover and center layers in FIG. 1 or 2 may include more thanone layer, i.e., the golf ball can be a conventional three-piece woundball, a two-piece ball, a ball having a multi-layer core and anintermediate layer or layers, etc.

Also, FIG. 3 shows a golf ball 16 of the present invention including alarge core 18, a cover 22, and an inner cover layer 20. In oneembodiment, the core 18 includes a center and an outer core layer. Thecover 22 and/or inner cover layer 20 may be formed from the compositionof the invention. In one embodiment, the cover 22 is formed from thecomposition of the invention.

In another embodiment, as shown in FIG. 4, a golf ball 24 of the presentinvention can include a large core having a center 26 and anintermediate layer 28 disposed underneath a dual cover having an innercover layer 30 and an outer cover layer 32. The inner cover layer 30and/or outer cover layer 32 is formed from the compositions of theinvention. In one embodiment, the outer cover layer 32 is formed fromthe compositions of the invention. Further, any of the figures detailedherein may include embodiments wherein an optional wound layer isdisposed between the center and the core of the golf ball.

Other non-limiting examples of suitable types of ball constructions thatmay be used with the present invention include those described in U.S.Pat. Nos. 6,056,842, 5,688,191, 5,713,801, 5,803,831, 5,885,172,5,919,100, 5,965,669, 5,981,654, 5,981,658, and 6,149,535, as well as inPublication Nos. US2001/0009310 A1, US2002/0025862, and US2002/0028885.The entire disclosures of these patents and published patentapplications are incorporated by reference herein.

Golf Ball Core Layer(s)

The cores of the golf balls formed according to the invention may besolid, semi-solid, hollow, fluid-filled or powder-filled, one-piece ormulti-component cores. As used herein, the term “fluid” includes aliquid, a paste, a gel, a gas, or any combination thereof; the term“fluid-filled” includes hollow centers or cores; and the term“semi-solid” refers to a paste, a gel, or the like.

The core may have a diameter of about 1.5 inches to about 1.62 inchesand the cover layer thickness may range from about 0.03 inches to about0.06 inches. The core compression preferably ranges from about 30 toabout 120 atti and the overall ball compression is about 50 to about110.

Any core material known to one of ordinary skill in that art is suitablefor use in the golf balls of the invention. Suitable core materialsinclude thermoset materials, such as rubber, styrene butadiene,polybutadiene, isoprene, polyisoprene, trans-isoprene, as well asthermoplastics such as ionomer resins, polyamides or polyesters, andthermoplastic and thermoset polyurethane elastomers. For example,butadiene rubber, which, in an uncured state, typically has a Mooneyviscosity (measured according to ASTM D1646-99) greater than about 20,preferably greater than about 30, and more preferably greater than about40, may be used in one or more core layers of the golf balls preparedaccording to the present invention. In addition, the compositions of theinvention may be incorporated the core.

Golf Ball Intermediate Layer(s)

When the golf ball of the present invention includes an intermediatelayer, such as an inner cover layer or outer core layer, i.e., anylayer(s) disposed between the inner core and the outer cover of a golfball, this layer may be formed from the composition of the invention.For example, an intermediate layer or inner cover layer having athickness of about 0.015 inches to about 0.06 inches may be disposedabout a core. In this aspect of the invention, the core, which has adiameter ranging from about 1.5 inches to about 1.59 inches, may also beformed from a composition of the invention or, in the alternative, froma conventional rubber composition. The inner ball may be covered by acastable thermoset or injection moldable thermoplastic material or anyof the other cover materials discussed below. In this aspect of theinvention, the cover may have a thickness of about 0.02 inches to about0.045 inches, preferably about 0.025 inches to about 0.04 inches. Thecore compression is about 30 to about 110 atti, preferably about 50 toabout 100 atti, and the overall ball compression preferably ranges fromabout 50 to about 100 atti.

When not formed from the composition of the invention, the intermediatelayer may be formed from a number of thermoplastic and thermosettingmaterials. For example, the intermediate layer(s) may be formed, atleast in part, from one or more homopolymeric or copolymeric materials,such as ionomers, primarily or fully non-ionomeric thermoplasticmaterials, vinyl resins, polyolefins, polyurethanes, polyureas, such asthose disclosed in U.S. Pat. No. 5,484,870, polyamides, acrylic resinsand blends thereof, olefinic thermoplastic rubbers, block copolymers ofstyrene and butadiene, isoprene or ethylene-butylene rubber,copoly(ether-amide), such as PEBAX, sold by Arkema, Inc. ofPhiladelphia, Pa., polyphenylene oxide resins or blends thereof, andthermoplastic polyesters.

For example, the intermediate layer may be formed of low acid ionomers,such as those described in U.S. Pat. Nos. 6,506,130 and 6,503,156, highacid ionomers, highly neutralized polymers, such as those disclosed inU.S. Patent Publication Nos. 2001/0018375 and 2001/0019971, or mixturesthereof. The intermediate layer may also be formed from the compositionsas disclosed in U.S. Pat. No. 5,688,191. The entire disclosures of thesepatents and publications are incorporated herein by express referencethereto.

The intermediate layer may also include a wound layer formed from atensioned thread material. The thread may be single-ply or may includetwo or more plies. Suitable thread materials include, but are notlimited to, fiber, glass, carbon, polyether urea, polyether blockcopolymers, polyester urea, polyester block copolymers, syndiotactic- orisotactic-poly(propylene), polyethylene, polyamide, poly(oxymethylene),polyketone, poly(ethylene terephthalate), poly(p-phenyleneterephthalamide), poly(acrylonitrile), diaminodicyclohexylmethane,dodecanedicarboxylic acid, natural rubber, polyisoprene rubber,styrene-butadiene copolymers, styrene-propylene-diene copolymers,another synthetic rubber, or block, graft, random, alternating, brush,multi-arm star, branched, or dendritic copolymers, or mixtures thereof.Those of ordinary skill in the art are aware of the process forproducing thread materials for use with the present invention.

Golf Ball Cover Layer(s)

The cover provides the interface between the ball and a club. Propertiesthat are desirable for the cover are good moldability, high abrasionresistance, high impact resistance, high tear strength, high resilience,and good mold release, among others. The cover layer may be formed, atleast in part, from a composition of the invention. For example, thepresent invention contemplates a golf ball having a large core ofpolybutadiene and a thin cover formed from the composition of theinvention.

When the compositions of the invention are incorporated into a core orintermediate/inner cover layer, however, the cover may be formed fromone or more homopolymeric or copolymeric materials as discussed in thesection above pertaining to the intermediate layer. The cover may alsobe at least partially formed from a polybutadiene reaction product, asdiscussed above with respect to the core. Golf balls according to theinvention may also be formed having a cover of polyurethane, polyurea,and polybutadiene materials discussed in U.S. Pat. No. 6,835,794.

Layer Formation

The golf balls of the invention may be formed using a variety ofapplication techniques such as compression molding, flip molding,injection molding, retractable pin injection molding, reaction injectionmolding (RIM), liquid injection molding (LIM), casting, vacuum forming,powder coating, flow coating, spin coating, dipping, spraying, and thelike. Conventionally, compression molding and injection molding areapplied to thermoplastic materials, whereas RIM, liquid injectionmolding, and casting are employed on thermoset materials. These andother manufacture methods are disclosed in U.S. Pat. Nos. 6,207,784 and5,484,870, the disclosures of which are incorporated herein by referencein their entirety.

Cores of the golf balls of the invention may be formed by any suitablemethod known to those of ordinary skill in art. When the cores areformed from a thermoset material, compression molding is a particularlysuitable method of forming the core. In a thermoplastic core embodiment,on the other hand, the cores may be injection molded. Furthermore, U.S.Pat. Nos. 6,180,040 and 6,180,722 disclose methods of preparing dualcore golf balls. The disclosures of these patents are herebyincorporated by reference in their entirety.

The intermediate layer and/or cover layer may also be formed using anysuitable method known to those of ordinary skill in the art. Forexample, an intermediate layer may be formed by blow molding and coveredwith a dimpled cover layer formed by injection molding, compressionmolding, casting, vacuum forming, powder coating, and the like.

For example, when the compositions of the invention are formed into acover, the prepolymer and curative blend may be mixed and poured into amold. The temperature of the mold preferably ranges from about 100° F.to about 250° F. In one embodiment, the mold temperature ranges fromabout 120° F. to about 200° F. In another embodiment, the temperature ofthe mold ranges from about 140° F. to about 180° F. In still anotherembodiment, the mold temperature is about 150° F. to about 170° F.

The gel times preferably range from about 10 seconds to about 200seconds. “Gel time” as used herein represents the amount of time, fromthe time the components are mixed to the time that the material ispolymerized sufficiently that, if touched lightly with the edge of ametal spatula, no material adheres to the spatula, although the materialis rubbery enough that an indentation in the material could easily andvisibly be made. In contrast, “demold time” is the time at which themolded article is demolded without damage. In one embodiment, the geltime is from about 30 seconds to about 150 seconds. In anotherembodiment, the gel time is from about 40 seconds to about 130 seconds.In still another embodiment, the gel time is from about 45 seconds toabout 120 seconds. Those of ordinary skill in the art are aware that theshorter gel times relate to higher NCO content. For example, aconventional polyurethane or polyurea composition with an NCO content ofabout 9 percent will typically result in a faster reaction rate and,thus, gel time of about 45 seconds.

The use of various dimple patterns and profiles provides a relativelyeffective way to modify the aerodynamic characteristics of a golf ball.As such, the manner in which the dimples are arranged on the surface ofthe ball can be by any available method. For instance, the ball may havean icosahedron-based pattern, such as described in U.S. Pat. No.4,560,168, or an octahedral-based dimple patterns as described in U.S.Pat. No. 4,960,281. Furthermore, the resultant golf balls preparedaccording to the invention typically will have dimple coverage greaterthan about 60 percent, preferably greater than about 65 percent, andmore preferably greater than about 70 percent.

Golf Ball Post-Processing

The golf balls of the present invention may be painted, coated, orsurface treated for further benefits. For example, golf balls may becoated with urethanes, urethane hybrids, ureas, urea hybrids, epoxies,polyesters, acrylics, or combinations thereof in order to obtain anextremely smooth, tack-free surface. If desired, more than one coatinglayer can be used. The coating layer(s) may be applied by any suitablemethod known to those of ordinary skill in the art. In one embodiment,the coating layer(s) is applied to the golf ball cover by an in-moldcoating process, such as described in U.S. Pat. No. 5,849,168, which isincorporated in its entirety by reference herein.

Any of the golf ball layers may be surface treated by conventionalmethods including blasting, mechanical abrasion, corona discharge,plasma treatment, and the like, and combinations thereof. In fact,because low surface energy, or surface tension, is a key feature ofpolysiloxanes, layers formed from the compositions of the invention maybe surface treated according to U.S. Patent Publication No.2003/0199337, the disclosure of which is incorporated in its entirety byreference herein.

Golf Ball Properties

The properties such as core diameter, intermediate layer and cover layerthickness, hardness, and compression have been found to effect playcharacteristics such as spin, initial velocity and feel of the presentgolf balls.

Component Dimensions

Dimensions of golf ball components, i.e., thickness and diameter, mayvary depending on the desired properties. For the purposes of theinvention, any layer thickness may be employed. For example, the presentinvention relates to golf balls of any size, although the golf ballpreferably meets USGA standards of size and weight. While “The Rules ofGolf” by the USGA dictate specifications that limit the size of acompetition golf ball to more than 1.680 inches in diameter, golf ballsof any size can be used for leisure golf play. The preferred diameter ofthe golf balls is from about 1.680 inches to about 1.800 inches. Themore preferred diameter is from about 1.680 inches to about 1.760inches. A diameter of from about 1.680 inches (43 mm) to about 1.740inches (44 mm) is most preferred, however diameters anywhere in therange of from 1.700 to about 1.950 inches can be used.

Preferably, the overall diameter of the core and all intermediate layersis about 80 percent to about 98 percent of the overall diameter of thefinished ball. The core may have a diameter ranging from about 0.09inches to about 1.65 inches. In one embodiment, the diameter of the coreof the present invention is about 1.2 inches to about 1.630 inches. Forexample, when part of a two-piece ball according to invention, the coremay have a diameter ranging from about 1.5 inches to about 1.62 inches.In another embodiment, the diameter of the core is about 1.3 inches toabout 1.6 inches, preferably from about 1.39 inches to about 1.6 inches,and more preferably from about 1.5 inches to about 1.6 inches. In yetanother embodiment, the core has a diameter of about 1.55 inches toabout 1.65 inches, preferably about 1.55 inches to about 1.60 inches. Inone embodiment, the core diameter is about 1.59 inches or greater. Inanother embodiment, the diameter of the core is about 1.64 inches orless.

When the core includes an inner core layer and an outer core layer, theinner core layer is preferably about 0.5 inches or greater and the outercore layer preferably has a thickness of about 0.1 inches or greater.For example, when part of a multi-layer ball according to invention, thecenter may have a diameter ranging from about 0.5 inches to about 1.30inches and the outer core layer may have a diameter ranging from about0.12 inches to about 0.5 inches. In one embodiment, the inner core layerhas a diameter from about 0.09 inches to about 1.2 inches and the outercore layer has a thickness from about 0.1 inches to about 0.8 inches. Inyet another embodiment, the inner core layer diameter is from about0.095 inches to about 1.1 inches and the outer core layer has athickness of about 0.20 inches to about 0.03 inches.

The cover typically has a thickness to provide sufficient strength, goodperformance characteristics, and durability. In one embodiment, thecover thickness is from about 0.02 inches to about 0.12 inches,preferably about 0.1 inches or less. For example, when part of atwo-piece ball according to invention, the cover may have a thicknessranging from about 0.03 inches to about 0.09 inches. In anotherembodiment, the cover thickness is about 0.05 inches or less, preferablyfrom about 0.02 inches to about 0.05 inches, and more preferably about0.02 inches and about 0.045 inches.

The range of thicknesses for an intermediate layer of a golf ball islarge because of the vast possibilities when using an intermediatelayer, i.e., as an outer core layer, an inner cover layer, or amoisture/vapor barrier layer. When used in a golf ball of the invention,the intermediate layer, or inner cover layer, may have a thickness about0.3 inches or less. In one embodiment, the thickness of the intermediatelayer is from about 0.002 inches to about 0.1 inches, preferably about0.01 inches or greater. For example, when part of a three-piece ball ormulti-layer ball according to invention, the intermediate layer and/orinner cover layer may have a thickness ranging from about 0.015 inchesto about 0.06 inches. In another embodiment, the intermediate layerthickness is about 0.05 inches or less, more preferably about 0.01inches to about 0.045 inches.

Hardness

Because the compositions of the invention may be used in any layer of agolf ball, the golf ball construction, physical properties, andresulting performance may vary greatly depending on the layer(s) of theball that include the compositions of the invention.

The cores included in golf balls of the present invention may havevarying hardnesses depending on the particular golf ball construction.In one embodiment, the core hardness is at least about 15 Shore A,preferably about 30 Shore A, as measured on a formed sphere. In anotherembodiment, the core has a hardness of about 50 Shore A to about 90Shore D. In yet another embodiment, the hardness of the core is about 80Shore D or less. Preferably, the core has a hardness about 30 to about65 Shore D, and more preferably, the core has a hardness about 35 toabout 60 Shore D. In another embodiment, the core has a Shore C hardnessof from about 30 Shore C to greater than 90 Shore C, more preferablyabout 40 Shore C to 92 Shore C, and most preferably about 50 Shore C to91 Shore C.

The intermediate layer(s) of the present invention may also vary inhardness depending on the specific construction of the ball. In oneembodiment, the hardness of the intermediate layer is about 30 Shore Dor greater. In another embodiment, the hardness of the intermediatelayer is about 90 Shore D or less, preferably about 80 Shore D or less,and more preferably about 70 Shore D or less. For example, when anintermediate layer is formed from the composition of the invention, thehardness of the intermediate layer may be about 65 Shore D or less,preferably ranging from about 35 Shore D to about 60 Shore D. In yetanother embodiment, the hardness of the intermediate layer is about 50Shore D or greater, preferably about 55 Shore D or greater. In oneembodiment, the intermediate layer hardness is from about 55 Shore D toabout 65 Shore D. The intermediate layer may also be about 65 Shore D orgreater. For example, a golf ball of the invention may include an innercover formed from a rosin-modified polymeric composition of theinvention having a hardness of about 60 Shore D to about 75 Shore D.

As with the core and intermediate layers, the cover hardness may varydepending on the construction and desired characteristics of the golfball. The ratio of cover hardness to inner ball hardness is a primaryvariable used to control the aerodynamics of a ball and, in particular,the spin of a ball. In general, the harder the inner ball, the greaterthe driver spin and the softer the cover, the greater the driver spin.

For example, when the intermediate layer is intended to be the hardestpoint in the ball, e.g., about 60 Shore D to about 75 Shore D, the covermaterial may have a hardness of about 20 Shore D or greater, preferablyabout 25 Shore D or greater, and more preferably about 30 Shore D orgreater, as measured on the slab. In another embodiment, the coveritself has a hardness of about 30 Shore D or greater. In particular, thecover may be from about 30 Shore D to about 70 Shore D. In oneembodiment, the cover has a hardness of about 40 Shore D to about 65Shore D, and in another embodiment, about 40 Shore to about 55 Shore D.In another aspect of the invention, the cover has a hardness less thanabout 45 Shore D, preferably less than about 40 Shore D, and morepreferably about 25 Shore D to about 40 Shore D. In one embodiment, thecover has a hardness from about 30 Shore D to about 40 Shore D.

In one embodiment, the cover hardness is about 60 Shore D or greater. Inanother embodiment, the cover hardness is about 62 Shore D or greater.In still another embodiment, the cover hardness is about 64 Shore D orgreater. For example, the cover hardness may range from about 55 Shore Dto about 85 Shore D. In another embodiment, the cover hardness is about60 Shore D to about 80 Shore D. This range of hardness may be used in a2-piece ball, i.e., a ball with a core and a cover, as well as amultilayer ball, e.g., a ball with one or more intermediate layersdisposed between the core and the cover.

Compression

Compression is an important factor in golf ball design. For example, thecompression of the core can affect the spin rate of the ball off thedriver, as well as the feel of the ball when struck with the club. Asdisclosed in Jeff Dalton's Compression by Any Other Name, Science andGolf IV, Proceedings of the World Scientific Congress of Golf (EricThain ed., Routledge, 2002) (“J. Dalton”), several different methods canbe used to measure compression, including Atti compression, Riehlecompression, load/deflection measurements at a variety of fixed loadsand offsets, and effective modulus. For purposes of the presentinvention, “compression” refers to Atti compression and is measuredaccording to a known procedure, using an Atti compression test device,wherein a piston is used to compress a ball against a spring. The travelof the piston is fixed and the deflection of the spring is measured. Themeasurement of the deflection of the spring does not begin with itscontact with the ball; rather, there is an offset of approximately thefirst 1.25 mm (0.05 inches) of the spring's deflection. Very lowstiffness cores will not cause the spring to deflect by more than 1.25mm and therefore have a zero compression measurement. The Atticompression tester is designed to measure objects having a diameter of42.7 mm (1.68 inches); thus, smaller objects, such as golf ball cores,must be shimmed to a total height of 42.7 mm to obtain an accuratereading. Conversion from Atti compression to Riehle (cores), Riehle(balls), 100 kg deflection, 130-10 kg deflection or effective moduluscan be carried out according to the formulas given in J. Dalton.

As known to those of ordinary skill in the art, compression values aredependent on the diameter of the component being measured. The Atticompression of the core, or portion of the core, of golf balls preparedaccording to the invention may range from about 30 to about 110 atti,preferably about 50 to about 100 atti. In one embodiment, the corecompression is less than about 80, preferably less than about 75. Inanother embodiment, the core compression is from about 40 to about 80,preferably from about 50 to about 70. In yet another embodiment, thecore compression is preferably below about 50, and more preferably belowabout 25.

In an alternative, low compression embodiment, the core has acompression less than about 20, more preferably less than about 10, andmost preferably, 0. As known to those of ordinary skill in the art,however, the cores generated according to the present invention may bebelow the measurement of the Atti Compression Gauge.

In one embodiment, golf balls of the invention preferably have an Atticompression of about 55 or greater, preferably from about 60 to about120. In another embodiment, the Atti compression of the golf balls ofthe invention is at least about 40, preferably from about 50 to 120, andmore preferably from about 50 to 100. In yet another embodiment, thecompression of the golf balls of the invention is about 75 or greaterand about 95 or less. For example, a preferred golf ball of theinvention may have a compression from about 80 to about 95.

Coefficient of Restitution

The present invention contemplates golf balls having CORs from about0.700 to about 0.850 at an inbound velocity of about 125 ft/sec. In oneembodiment, the COR is about 0.750 or greater, preferably about 0.780 orgreater. In another embodiment, the ball has a COR of about 0.800 orgreater. In yet another embodiment, the COR of the balls of theinvention is about 0.800 to about 0.815.

Alternatively, the maximum COR of the ball is one that does not causethe golf ball to exceed initial velocity requirements established byregulating entities such as the USGA. As used herein, the term“coefficient of restitution” (CoR) is calculated by dividing the reboundvelocity of the golf ball by the incoming velocity when a golf ball isshot out of an air cannon. The COR testing is conducted over a range ofincoming velocities and determined at an inbound velocity of 125 ft/s.Another measure of this resilience is the “loss tangent,” or tan δ,which is obtained when measuring the dynamic stiffness of an object.Loss tangent and terminology relating to such dynamic properties istypically described according to ASTM D4092-90. Thus, a lower losstangent indicates a higher resiliency, thereby indicating a higherrebound capacity. Low loss tangent indicates that most of the energyimparted to a golf ball from the club is converted to dynamic energy,i.e., launch velocity and resulting longer distance. The rigidity orcompressive stiffness of a golf ball may be measured, for example, bythe dynamic stiffness. A higher dynamic stiffness indicates a highercompressive stiffness. To produce golf balls having a desirablecompressive stiffness, the dynamic stiffness of the crosslinked materialshould be less than about 50,000 N/m at −50° C. Preferably, the dynamicstiffness should be between about 10,000 and 40,000 N/m at −50° C., morepreferably, the dynamic stiffness should be between about 20,000 and30,000 N/m at −50° C.

Other than in the operating examples, or unless otherwise expresslyspecified, all of the numerical ranges, amounts, values and percentagessuch as those for amounts of materials, times and temperatures ofreaction, ratios of amounts, values for molecular weight (whether numberaverage molecular weight (“Mn”) or weight average molecular weight(“Mw”), and others in the following portion of the specification may beread as if prefaced by the word “about” even though the term “about” maynot expressly appear with the value, amount or range. Accordingly,unless indicated to the contrary, the numerical parameters set forth inthe following specification and attached claims are approximations thatmay vary depending upon the desired properties sought to be obtained bythe present invention. At the very least, and not as an attempt to limitthe application of the doctrine of equivalents to the scope of theclaims, each numerical parameter should at least be construed in lightof the number of reported significant digits and by applying ordinaryrounding techniques.

Notwithstanding that the numerical ranges and parameters setting forththe broad scope of the invention are approximations, the numericalvalues set forth in the specific examples are reported as precisely aspossible. Any numerical value, however, inherently contain certainerrors necessarily resulting from the standard deviation found in theirrespective testing measurements. Furthermore, when numerical ranges ofvarying scope are set forth herein, it is contemplated that anycombination of these values inclusive of the recited values may be used.

The invention described and claimed herein is not to be limited in scopeby the specific embodiments herein disclosed, since these embodimentsare intended as illustrations of several aspects of the invention. Anyequivalent embodiments are intended to be within the scope of thisinvention. For example, the compositions of the invention may also beused in golf equipment such as putter inserts, golf club heads andportions thereof, golf shoe portions, and golf bag portions. Indeed,various modifications of the invention in addition to those shown anddescribed herein will become apparent to those skilled in the art fromthe foregoing description. Such modifications are also intended to fallwithin the scope of the appended claims. All patents and patentapplications cited in the foregoing text are expressly incorporateherein by reference in their entirety.

What is claimed is:
 1. A golf ball comprising at least one layercomprising a blend of a high-crystalline acid polymer and a compositioncomprising: a polyurea prepolymer formed from the reaction product of adiisocyanate and an amine-terminated component; wherein the prepolymercomprises a neutralizing agent comprising dialkyl sulfate; a curativecomprising: an amine-terminated curing agent having at least one of thefollowing general formulas:H₂N—R₁—NH₂;R₂HN—R₁—NHR₂;R₃R₂N—R₁—NR₂R₃;H₂N—R₁—NHR₂;R₃R₂N—R₁—NH₂; orR₃R₂N—R₁—NHR₂ where R₁ comprises unsubstituted or substituted straightchain or branched aliphatic groups, unsubstituted or substitutedaromatic groups, or mixtures thereof, wherein R₂ and R₃ independentlycomprise an alkyl group, an aryl group, or an aralkyl group, and whereinthe amine-terminated curing agent further comprises about 5 percent toabout 25 percent precursor cationic groups by weight of theamine-terminated curing agent; and wherein between about 20 percent and70 percent of the precursor cationic groups are neutralized.
 2. The golfball of claim 1, wherein the curative further comprises a flow modifier.3. The golf ball of claim 1, wherein the precursor cationic groupscomprise a sulfide.
 4. The golf ball of claim 1, wherein the golf ballcomprises a core, an intermediate layer disposed about the core to forman inner ball, and a cover disposed about the inner ball, and whereinthe cover is formed from the composition.
 5. The golf ball of claim 4,wherein the intermediate layer is formed from a thermoplastic material.6. The golf ball of claim 1, wherein the golf ball comprises a core, anintermediate layer disposed about the core to form an inner ball, and acover disposed about the inner ball, and wherein the intermediate layeris formed from the composition.
 7. A golf ball comprising a core and acover, wherein the cover comprises a blend of a high-crystalline acidpolymer and a composition comprising: a polyurea prepolymer formed fromthe reaction product of a diisocyanate and an amine terminatedcomponent; a curative comprising: an amine-terminated curing agentcomprising between about 1 percent to about 50 percent precursorcationic groups by weight of the amine-terminated curing agent; andwherein the prepolymer comprises a dialkyl sulfate.
 8. The golf ball ofclaim 7, wherein the cover comprises an inner cover layer and an outercover layer.
 9. The golf ball of claim 8, wherein the inner cover layercomprises the composition.
 10. The golf ball of claim 8, wherein theouter cover layer comprises the composition.
 11. The golf ball of claim8, wherein between about 20 percent and 70 percent of the precursorcationic groups are neutralized.
 12. The golf ball of claim 8, whereinthe composition further comprises a flow modifier.
 13. The golf ball ofclaim 12, wherein greater than about 70 percent of the precursorcationic groups are neutralized.
 14. The golf ball of claim 8, whereinthe precursor cationic groups comprise ═S.
 15. The golf ball of claim 8,wherein the amine-terminated curing agent comprises between about 5percent to about 25 percent precursor cationic groups by weight of theamine-terminated curing agent.
 16. The golf ball of claim 8, wherein thecomposition is thermoplastic.
 17. The golf ball of claim 8, wherein thecomposition is thermoset.